When you say online, do you mean to your LMS? Also, what format are you using for captions (SRT, XML, etc.)? When I was using SRT for my caption format, they did not work with my LMS (Pathlore), so I had to convert them all to XML, which wasn’t all that bad more than it was an annoyance.
If you ever need it, there’s a great one file at a time converter, SRT to XML for JW Player. When I was converting, I copied all the text from the SRT (including blank lines), pasted it into the box, then downloaded. Make sure the “No CDATA” box is checked.